Shaded pole electric coin selector



April 3, 1934. w. K. KLOSE SHADED POLE ELECTRIC COIN SELECTOR Fild March7, 1932 g'wuentoa;

6. l IS A 2 I m m O l Patented Apr. 3, 1934 UNITED STATES PATENT OFFICEone-half to John M.

Nebr.

Alexander, Lincoln,

Application March 7, 1932, Serial, No. 597,314

9 Claims.

' My invention relates to electric coin selectors, its primary objectbeing the provision of a device for conducting coins through-a magneticfield for the purpose of accepting some coins and rejecting others.

- Another of my objects is to provide a rotating magnetic field throughwhich the coins are to be passed so that various directional impulseswill be imparted to the coins, depending on the metal of which the coinsconsist.

Another of my objects is the provision of a coin chute with an abutmentbelow the coin chute so positioned that the coin will fall onto theabutment at one side or the other of its vertical center lineso that itmust roll off in one direction or the other, the different directionalimpulses having been imparted to the coins before they reach thisabutment.

Another of my objects is the provision of a coin selector having meansfor adjustment to coins of various metals and alloys in accordance withthe resistivity and the weight of the metal or alloy.

Another of my objects is the provision of a time switch which, on theinsertion of a coin, turns on the current and which automatically turnsoff the current after a predetermined time interval, the switch beingadjustable to difierent time intervals.

Another of my objects is to provide a rotating magnetic field betweenthe poles of a single phase alternating current electromagnet by meansof shading coils surrounding portions of the pole pieces.

Having in view these objects and others which will bepointed out in thefollowing description, I will now refer to the drawing, in which Figure1 is a view in perspective and partly diagrammatic of my coin selector,parts being broken away to disclose parts which would otherwise beconcealed.

Figure 2 is a view in perspective of an end fragment of one of the polepieces of the electromagnet, showing particularly the position andnature of the shading coil.

Figure 3 is a diagrammatic view of the pole pieces showing the shadingcoils in position and indicating the lines of force in the magneticfield when the primary circuit is at its highest intensity.

Figure 4 is a view similar to Figure 3 but showing the oppositedirections of the lines 01' force 5 between the shaded portions of thepoles and the unshaded portions at the moment when a direc-.

tional change of the flow in the primary circuit has taken place andwhen this current is still at its minimum intensity.

Figure 5 is a view in perspective of an end fragment of theelectromagnet and of the shading coil and showing a metal disk in themagnetic field and showing also the direction of the induced 'eddycurrents in theshading coil and the disk.

Figure 6 is a. view in perspective of the time switch mechanism.

For receiving, conducting and discharging the coins, I provide a member10 having a downwardly and rearwardly inclined chute 11 with a mouth at12 and with a forward outlet 13 and a rearward outlet 14. The member 10is made from a suitable dielectric, this being in the present instancein the form of two plateswhich are so grooved that the passageway 11 isformed between them when the plates are secured together. A coinintroduced into the mouth 12 will naturally roll down the downwardly andrearwardly inclined chute 11 until it strikes the back wall of thatchute. At this point it bounces very slightly due to the elasticity ofthe metal and of the material of the member 10 and it then fallsdownwardly into the open space in the lower portion of the member 10.

The pin 15- is positioned in the direct path of the falling coin but itis slightly offset from the 30 vertical center line of the falling coin.Its position "is such that the preponderance of weight of the coin is tothe front of the pin 15. This insures that the coin will fall throughthe outlet 13. The problem of coin selection thus resolves 5 itselfintogiving the desired coin a distinct rearward impulse so that when itstrikes the pin 15, the preponderance of weight will be on the rear sideof the pi.. 15, coins of other metals or alloys being not responsive tothat impulse. A coin which is. thus selected must fall through theopening 14.

The invention herein described must, however, not be confused with thosecoin selectors which depend for their operation on the elasticity of 5the coin or with those coin selectors which depend on the retardingaction of a magnetic held on a coin passing through this field. It istrue that the bouncing effect of the coin must be taken intoconsideration in the design of the machine but this invention makes nouse of this property for the selection of the coins.

The walls of the member 10 are provided with apertures for; thereception of the poles of an electromagnet 16 which is energized by acoil 17. The magnet is in laminated form and is built up from metallicsheets having high permeability, low remanence, small coercive force andhigh resistivity. The sheets are insulated from each other as by varnishbetween the layers. 1

of magnetic induction made by Faraday, namely that any metallicconductor passing through a magnetic field of high intensity has itsmotion retarded. To make this magnetic field not only oscillating butrotating as well I have, in this in vention introduced shading coilsconsisting. of short circuited rings insulated from actual contact withthe metal of the pole piece and madeof a metal of low resistivity,around portions of the pole pieces of the electromagnet. In principlethese shading coils enclose a portion of the total magnetic flux of themagnet. Conse-' quently, when a directional change takes place in themagnetic lines due to the continuous changes of directional flow ofalternating current in the energizing coil 1'7, there are caused tofiow, in the shading coils 18, currents which flow in a directiontending to oppose the change of the magnetic flux in the electromagnet16. These induced currents in the shading coils establish a localmagnetic flux and due to this flux they cause that portion of the poleswhich they enclose to retain their particular polarity for aninfinitesimal period of time longer than thatv portion which is notenclosed by such coils, and they consequently cause a continuous laggingof the polarity changes in the extremities of these shaded portions.This lagging is commercially referred to as the splitting of the phaseand causes a single phase electromagnet to act the same as a two-phasemagnet, and creates the rotating magnetic field on which this inventiondepends for imparting a lateral and rotary motion for the selection ofcoins. The effect of this rotating magnetic field on coins of variousmetals is very marked, depending on the strength of the field, on theresistivity of the metal andon the weight of the coin. V

Referring now to Figure 1, a coin of any metal or alloy passing down thechute 11'rolls downwardly and rearwardly until it strikes the back wallof the chute. It here comes momentarily to rest but almost immediatelytakes up its motion again in a downward direction. It now, however, cutsthrough the magnetic lines oscillating between the pole pieces of themagnet 16. Cutting through these lines of force causes eddy currents toflow in the coin as shown in Figure 5. These induced eddy currents inthe coin cause magnetic lines to emanate from the coin and cause polesto form on opposite faces and opposite sides of the coin. 7 I ,7 Taking,for example, the particular case shown in Figure 5, the direction shownfor the eddy current in the shading coil 18 establishes the fact that inthis particular case the main pole of the coinv and a north poleemanating from the right half of the coin. Due to the known fact thatopposite magnetic poles attract and like magnetic poles repel, itfollows that the left half of the coin in'Figure 5 is repelled from theleft portion of the pole piece and is attracted by the right handportion of the pole piece, and the right half of the coin is repelled bythe right hand portion of the pole piece. This combination of repulsionand attraction of forces causes the coin to move laterally toward theright, or

if restrained from going inthis direction and the field intensity ishigh enough and the re---; sistivity of the coin is low enough, to causein-' duced poles in the coin of a strength sufiicient to;- retain theweight of the metal, it will be set in rotation in its counterclockwisedirection when viewed as in Figure 5 and in clockwise direction whenviewed'as in Figure 1.

If now, for example, the coil 17 is adjusted to produce a field betweenthe poles of the magnet 16 of suitable strength for the selection ofsilver coins of United States mintage, this strength of the magneticfield would be made such as to be a trifle less than that required toinduce poles in the silver of sufficient intensity to retain the weightof the coin. Consequently the coin gradually slips downward through themagnetic field. In so doing, however, the magnetic poles induced in thesilver, as previously described, cause the coin to be pushed toward therear of the pin 15 so that it is discharged through the outlet 14.United States silver coins contain a certain percentage of copper and itis a known fact that -alloys have greater resistivity than any of theaction more positively insuring that the coin on striking the pin 15will pass through the discard outlet 13. On the other hand, coins ofless resistivity than that of coin silver, such as pure copper, will besuspended in the magnetic field and since its rearward motion would bestopped by the back wall of the chute 11, the coin, due to the polesemanating from it, will be set in rapid rotation.

- It will thus be seen that three effects on the coin are possible. Ifthe selector is adjusted for coins of any one metal or alloy, such asUnited States silver coins, then that coin and no other will reach theoutlet 14. All other coils will be either retained suspended-within themagnetic field or they will be discharged through the discard outlet 13.If the strength of the field remains constant, the disposition of thecoins will depend largely on their resistivity and their weight. Coppercoins will be suspended because of their low resistivity. Aluminum coinsare also suspended in spite of their higher resistivity, the reason forthis being the extremely light weight of such coins.

For adjusting the selector to coins of various metals and alloys, Iprovide means for cutting out some of the coils of the primary circuit17. This may be done in any one of the conventional ways, the showing inFigure 1 being merely illustrative of a tap switch 20 for closing thecircuit through any desired number of coils. In this manner the strengthof the magnetic field may be. adjusted to coins of any desired metal oralloy.

Coins which remain suspended in the magnetic field would remain sosuspended indefinitely until the primary current is cut oiT. Theshutting off of the primary circuit would result in the natural fall ofthe coin which would thus strike the pin 15 in such a' manner as tocause it to fall through the discard outlet 13. A switch is thereforeintroduced into the system so that the circuit will automatically bebroken after a predetermined time interval. Referring to Figures 1 and6, it will be seen that a plunger 21 passes into the chute 11. Thisplunger 21 is pivotally connected to a support 22 which in turn ispivotally secured to a fixed member 23. The mercury switch 24 is securedto the support 22, its conductors 25 and 26 passing through the support22. A coin introduced through the mouth 12 of the chute will raise theplunger 21 to theposition shown in Figure 6. In this position the switch24 is level so that the mercury will turn on the current. In

other words the current is turned on automatically by the insertion ofthe coin in the mouth 12. The support 22 is, however, connected with apiston 2'7 which is movable in a cylinder 28 having a needle valve 29.The weights of the various parts will naturally tend to restore themercury switch 24 to a position of such inclination as to break thecircuit. The rate of descent of the plunger is, of course, governed bythe rate of escape of the air in cylinder 28. By simple adjustment ofthe needle valve 29 the time interval may be adjusted. The breaking ofthe circuit through the automatic switch will instantly release anycoins which are held suspended in the magnetic field so that these coinswill fall through the discard outlet 13.

Having thus described my invention in such full, clear, and exact termsthat its construction and operation will be readily understood by othersskilled in the art to which it pertains, what I claim as new and desireto secure by Letters Patent or" the United States is:

1. In a coin selector, a chute for a coin. said chute having an edgewiseenlarged vertical delivery opening through which the coin is adapted-tofreely fall, a transverse abutment disposed across the lower end of thedelivery opening of the chute intermediate the edges thereof to arrestfalling coins and direct the same edgewise in one direction, and meansoperating in the enlarged end of the chute for axially turning coins,depending upon their alloy content, falling therethrough whereby thecoins when striking the transverse abutment are directed in an oppositedirection.

2. In a coin selector, a coin receiving member having a vertical passagetherein through which a coin may freely fall, an abutment carried by themember near the lower end of the passage in the path of the coin toreceive the lower edge of the falling coin thereagainst, said abutmentbeing offset toward one edge portion of the vertical passage tooverbalance the coin for discharge from the opposite edge portion of thepassage, and coin turning means operable in said passage above theabutment to axially turn the coin, depending upon its alloy content,while falling and in a direction to overbalance the coin on the abutmentin an opposite direction for discharge through the said first edgeportion of the passage.

3. In a coin selector, a coin receiving member having a vertical passagetherein through which a coin may freely fall, a transverse abutment inthe lower end of the passage toward one edge portion thereof to receivethe lower edge of a falling coin and deflect the same downwardly throughthe opposite edge portion of the passage, and a bi-pole magnet having arotating field between the poles disposed with the poles at oppositesides of the passage for receiving the falling coin therebetween,whereby the coin depending upon its alloy content may be axially rotatedto deflect the coin from the abutment downwardly through the said firstedge portion of the passage.

4. In a coin selector for the selection of coins of a predeterminedresistivity, a coin receiving member having a passage therethrough for afreely falling coin, an alternating current split phase electromagnetdisposed with its field intermediate the ends of the passageway to acton the falling coin and impart a rotary movement thereto dependent uponthe alloy content of the coin, and a deflector in the path 01 thefalling coin for deflecting coins of a higher or lower resistivity fromthe path taken by coins of the predetermined resistivity.

5. A coin selector for the selection of coins of a predeterminedresistivity, said coin selector including an alternating currentsplit-phase electromagnet, a passageway between the poles of saidelectromagnet for afalling metallic disc,means for causing the metallicdisc to enter said passageway edge-wise and in the projected plane ofits gravitational movement, and a deflector in the path of the fallingcoin for deflecting coins of a higher or lower resistivity from the pathtaken by coins of the predetermined resistivity.

, 6. A coin selector for the selection of coins of predeterminedresistivity, said coin selector including an alternating currentsplit-phase electromagnet, a passageway between the poles of saidelectromagnet for a falling metallic disc, means for causing themetallic disc to enter said passageway edgewise and in the projectedplane of its gravitational movement, said passageway confining themovement of displacement of the metallic disc to the downwardlyprojected plane of the disc, and a deflector in the path of the fallingcoin for deflecting coins of a higher or lower resistivity from the pathtaken by coins of the predetermined resistivity.

7. A coin selector including an alternating currentsplit-phaseelectromagnet, a passageway bedisc to enter said passagewayedgewise and in the projected plane of its gravitational movement, saidpassageway confining the movement of displacement of the metallic discto the downwardly projected plane of the disc, and means for divert ingcertain of the metallic discs out of their gravitational path inresponse to the combined rotating and oscillating field of saidelectromagnet.

8. A coin selector for the selection of coins of a predeterminedresistivity, said coin selector including an alternating currentelectromagnet, shading coils on portions of the pole pieces of saidmagnet for setting up a combined oscillating and rotating magnetic fieldbetween the poles of said magnet, a passageway between the poles of saidmagnet for confining the movement of a metallic disc to a gravitationalpath inthe downwardly projected plane of the disc, and a deflectorinethe path of the falling coin for deflecting coins of a higher orlower resistivity from the path taken by coins of the predeterminedresistivity.

9. A coin selector including an alternating current split-phaseelectromagnet, a passageway between the poles of said magnet forconfining the movements of displacement of metallic discs to agravitational path in the downwardly projected plane of the discs, and adisplaced abutment in the path of the falling disc for causing the disc

